- Created by: Alice
- Created on: 07-04-15 14:56
Many metal compounds give distinctive flame colours, including compounds of:
Lithium - Crimson
Sodium - Yellow
Potassium - Lilac
Calcium - Red
Barium - Green
Sodium Hydroxide Solution
You can identify some metal ions in solution by adding sodium hydroxide solution.
The precipitates formed have distinctive colours.
Test for Carbonates, Halides and Sulfates
You can test for:
Carbonates by adding dilute acid
Halide ions by adding silver nitrate solution
Sulfates by adding barium chloride solution
You can use titrations to measure the volumes of acid and alkaline solutions that react with each other.
If you know the concentration of one reactant, you can use titration results to calculate the concentration of the other reactant.
Raw materials in Haber Process
The raw materials for the Haber process are nitrogen (obtained from the air) and hydrogen (often natural gas).
In the Haber process, nitrogen and hydrogen react together to form ammonia, NH³, in a reversible reaction.
The reaction takes pplace at high temperature (450°C), high pressure (200°C), and in the presence of an iron catalyst.
When a reversible reaction occurs in a closed system, equilibrium is reached when the reactions occur at the same rate in each direction.
Conditions of reaction
The relative amounts of the reacting substances at equilibrium depend on the conditions of the reaction.
Changing the temperature or pressure changes the amounts of substances at equilibrium.
Alcohols have the function group -OH.
They form neutral solutions in water, react with sodium to produce hydrogen, and burn in air.
Ethanol is oxidised to ethanoic acid.
Alcohols are used as fuels, solvents, and in drinks.
Carbonxylic acids have the functional group -COOH.
They form acidic solutions in water, react with carbonates to produce carbon dioxide, and react with alcohols to produce esters.
Carbonxylic acids are weak acids they do not ionise completely in water.
Ethanoic acid is the main acid in vinegar.
Esters have the functional group -COO-.
They are volatile compounds with distinctive smells.
They are used as flavourings and perfumes.